1. Field of the Invention
The present invention relates to a unique thermally stable lance for injecting particulate materials, such as desulfurizing agents and the like, into molten metal. Broadly, the lance of the invention includes a thermal insulating member, a special reinforcing rod disposed in the insulating member, a length of wire wound around the reinforcing rod and a tubular injection member or tube axially disposed in and essentially surrounded by the insulating member.
2. Description of the Prior Art
It is known to deoxidize molten metal by injecting deoxidizer material directly into the metal to be treated. (See, for example, U.S. Pat. No. 3,575,695). In such a method, the deoxidizer is injected into the molten metal below the surface thereof by means of a hollow cylindrical tube or lance which is encased in a refractory material.
In addition, it is known to desulfurize molten metal, usually iron, by injecting finely divided material, such as calcium carbide and the like, below the surface of the molten metal being treated by means of a hollow tube or lance. (See, for example, U.S. Pat. No. 2,692,196).
In each of the above-described processes a lance or tubular member is employed as the means of bringing the treating agent into contact with the molten metal. While the respective processes generally produce satisfactory results, much difficulty is experienced in connection with the equipment utilized, specifically the lance or tubular injection member. In fact, most lances presently available for the above-described general processes suffer from the fact that they are easily damaged or destroyed during usage or have a limited usable life.
Accordingly, it is the primary object of this invention to provide a lance which can be used to treat molten metal which is characterized by its thermal stability and relatively long usable life.
Additional objects of the invention will be apparent to those skilled in the art from a reading of the following description and claims.